According to the official imx6solox development board, I designed a similar development board,the PMIC MMPF0200F6AEP can be normal sometimes at the first time i power up the board , the led which controlled by VGEN3_2V8 is always blinking .the output voltage of MMPF0200 is not normal.but sometimes the PMIC outputs are all normal ,the led which controlled by VGEN3_2V8 is lighted nomally,then i measure the output voltage of MMPF0200 ,and find that the output are all normal.can you tell me why ?
Now I am not connected to a camera, HDMI, LCD, VGA or similar video interface.
When the system is powered up abnormally, the waveforms of VSNVS_3V0 and PWRON are as follows.
When the system is powered up normally, the waveforms of VSNVS_3V0 and PWRON are as follows
The yellow waveform is VSNVS_3V0
the PWRON SIGNAL AND 32K XI signal
I made three boards, one of which works fine no matter how the power is turned on.The other one, VGEN3_2V8 will flash when the power is first turned on, but if it is powered on quickly after power off, the power will work normally.I really don’t know why, do you have any thoughts?
Hi,
I have never seen this behavior before in application with no camera of other video source connected.
Since your issue is intermittent and not affecting all your boards, I’m thinking that the problem is not caused by a circuit or layout design, but it could be associated with a problem during the manufacture and/or solderability of the boards.
Have you tried to perform a swap test by changing the PMIC from a “good board” (or a new PMIC) to a “failing board” to see if this solves the problem of the failing board? This would confirm if the problem is the PMIC or the board itself.
Make sure the PMIC is properly soldered under the criteria below, otherwise the PMIC could be suffering damage while soldering.
Peak Package Body Temperature (PPT): 260C°
Maximum Time at Peak Temperatures: 40s
The Application note AN1902 provides guidelines for the handling and board mounting of QFN and SON packages including recommendations for printed-circuit board (PCB) design, soldering, and rework. You can find this document in the following link: https://www.nxp.com/docs/en/application-note/AN1902.pdf
Have a great day,
Jose
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Hi,
When you mention about the LED controlled by VGEN3_2V8, I’m assuming that you are referring to the PMIC-ON LED (D24) from the imx6solox Sabre Light, correct?
If this LED is blinking, then it means that the PMIC does not turn on properly, which makes sense that when you reset the system, it corrects the problem sometimes.
I have seen similar power-up issues when there is a camera, HDMI, LCD, VGA or similar video interface connected, typically this error is solved by first connecting the power connector and power-on the board and then connecting the video interfaces connectors.
Have a great day,
Jose
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Note:
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- We are following threads for 7 weeks after the last post, later replies are ignored
Please open a new thread and refer to the closed one, if you have a related question at a later point in time.
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